Tamping implement.



H. B. ANDR S.

TAMPING IMPLE T.

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Patented Jan. 10, 1911.

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HIRAM 1B. ANDREWS, OF MELROSE, MASSACHUSETTS, ASSIG NOR OF.ONE-HALF TO JOSEPH B. SIMPSON, 0F NEWTON, MASSACHUSETTS.

TAMTING IMPLEMENT.

Specification of Letters Patent. Patented Jan, 10, 1911,

Application filed June 29, 1910. Serial No. 569,427.

To'all whom 'it may concern:

Be it known that I, HIRAM'B. ANDREWS, a citizen of the United States, and a resident of Melrose, in the county of Middlesex and Commonwealth of Massachusetts, have invented an Improvement in Tamping Implements, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

This invention aims to provide an improved implement for tamping concrete and the like.

' According to the present practice, where a concrete floor or bottom is required to have a smoothly finished top surface the main body or layer of concrete is first laid with a mixture of stone or other aggregate, sand, cement and water, in proper proportions, and then after this main or foundation layer has partially or wholly set, there 7 is spread thereon a surface coating of sand,

cement and water, and richer in cement than the main or principal layer, which finish coating is smoothed off to give the required smoothness of finish to the top or exposed surface. This procedure involves excessive cost because of the larger percentage of cement required in the surface of filllSh coating, as compared with what is required for strength and body alone as in the principal layer, and also because of the additional labor involved in making up two batches of mixture and separately laying the same.

My invention comprehends a tamping implement of such construction that the stones forming a part of the principal layer of concrete may be so displacedas to cause sufficient sand, cement and water to come to the surface, to permit of the necessary smoothing of the layer to give the required finish at the surface without the necessity of applying a special layer, richer in cement, for that purpose alone.

The accompanying drawing illustrates a preferred embodiment of my invention, in which Figure l is a side view of the implement; and Fig. 2, a face View thereof.

Referring to the drawing, and the particular embodiment of my invention there shown, the implement comprises a head 1, provided with a suitable socket 2 for a handle 3, or a suitable handle may be provided in any other desired manner.

The head may be of any convenient dimensions, shape and material, although metal is preferred, the same being provided at its active face with a plurality of tamping projections 4, conveniently and preferably pyramidal in shape and quite closely arranged throughout the entire area of the face of said head. The apices of these pyramidal rojections are preferably pointed, so as rea ily to penetrate the concrete mass and permit the projections to enter between the stones or stony particles rather than drive them all bodily downward, as would be the tendency were the projections to have blunted or squared ends. Further to promote the entrance of these projections between the stones of the concrete, the angular pitch at the side. faces of the same is preferably about as shown, contrasted with a very low and broad based pyramidal or conical form, and the bases of adjacent pyramids are shown as preferably connected by easy fillets 5, to prevent, so far as possible, particles of stone from becoming wedged between the contracting surfaces at or near the bases of the projections. Obviously, a conical or other equivalent shape of projection might be used, although the pyramidal, so far as my present experience goes, furnishes the most satisfactory as well as the mosteconomical form to maintain.

In use, after the layer of concrete has been spread and roughly leveled with the customary straight edge, the workman proceeds to tamp the same from the top surface, the pyramidal projections of the tamping implement serving to displace and somewhat depress more or less of the stone contained in the layer, with the result that the freer sand,

cement and water contained in the mass, together with more or less of the finer particles of the stone, are forced or permitted to rise to the surface, leaving the latter in such condition that it may be smoothed off with a float or trowel substantially as the separately applied finish layer is smoothed off or finished, according to the present practice. So smooth is the surface so obtained that I have found it unnecessary to employ any separately applied finish layer.

Having described one embodiment of my invention, what I claim and desire-to secure by Letters Patent is:

1. {is a new article of manufacture, a tamplng implement provided at its active face with a plurality of tapering tamping 1 In testimony whereof, I have signed my projections, the bases of which are in contact name to this specification, in the presence of 10 with each other. 1 A f t two subscribing witnesses.

2. As a new artice or manu ac ure, a i

5 tamping implement provided at its active HIRAM ANDREWb' face with a plurality of tapering tamping Witnesses: projections, oined one to another at their EVEBET'I S. EMERY, bases by curved connecting surfaces. i ROBERT H. KAMMPLER. 

